View Code of Problem 23

#include<iostream>
using namespace std;
int main()
{   long int a[1000],m;
    
	while(cin>>m&&m!=0)
	{
		 a[1]=1;a[2]=2;
      for(int i=3;i<=m;i++)
     {
     	a[i]=a[i-1]+a[i-2]; 
	  }
		cout<<a[m]<<endl;
	}
 }